WebTailBench
MolmoWeb 8B 49.5% leads since Mar 2026 Fading Computer-use agents complete 609 hand-verified tasks on live websites across 11 categories, such as bookings, real estate and job search. A companion set of 111 harmful tasks tests refusals.
Released with Fara-7B. On 2026-05-12 Microsoft added a V2 split that refreshes calendar-bound task strings and rubrics for the same 609 tasks. The maker does not say V2 scores differ, so it stays one record.
- Level
- Everyday Most adults, without training
- Scored
- Graded by a model A language model scores each response, usually against a rubric.
- Answers
- Agent task Many steps in a terminal, browser, desktop, app, game or robot.
MolmoWeb 8B leads with 49.5% among models released by May 2026
Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.
The newest model with a score here came out in May 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 16 more
- 1 MolmoWeb 8B 49.5%
- 2
Fara1.5-27B 40.2% - 3 Fara-7B 38.4%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | MolmoWeb 8B | 49.5% | Mar 2026 | Model card | |
| 2 | Fara1.5-27B | 40.2% | May 2026 | Model card | |
| 3 | Fara-7B | 38.4% | Nov 2025 | Model card |
2 models have held number one since its release in Nov 2025
Lab claims count from the day the card came out, independent runs from the model’s release.
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Labs headline it less often now, last in May 2026
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| 21 May 2026 | Fara1.5-27B | 40.2 | WebTailBench |
| 24 Mar 2026 | MolmoWeb 8B | 49.5 | WebTailBench |
| 24 Nov 2025 | Fara-7B | 38.4 | WebTailBench |
3 system cards report it, from 2 labs
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| 18 Jun 2026 | Fara1.5-27B technical report | 40.2 | WebTailBench v1.5 Outcome Success, refreshed tasks and adapted critical-point verifier, 95% CI 3.0. Process Success 72.9 (Tables 3 and 7) | Capabilities |
| 9 Apr 2026 | MolmoWeb 8B technical report | 49.5 | WebTailBench, scored with the WebVoyager judge, 100 steps (Table 4) | Capabilities |
| 24 Nov 2025 | Fara-7B technical report | 38.4 | WebTailBench success rate, mean of 3 runs, macro and micro average both 38.4 over 11 segments (Table 9, Table 11) | Capabilities |
More in Computer and browser use
- BrowseComp In use Hard-to-find facts that need persistent web browsing. Short verifiable answers graded for exact correctness. Claude Fable 5 93.3%
- ScreenSpot-Pro In use GUI grounding on high-resolution professional-software screenshots. The model must locate the target UI element. GPT-6 Astra 92.7%
- AndroidWorld In use Agents complete 116 tasks across 20 real Android apps in an emulator. Each task checks the device's system state to judge success. GPT-6 Astra 100%
- OSWorld 2.1 In use Agents complete 108 long-horizon workflows across 31 self-hosted websites and desktop apps, averaging 318 tool calls. Scored by binary completion and checkpoint partial credit. Claude Opus 5.5 81.8%
- WebArena-Verified In use Agents complete 812 audited WebArena tasks on self-hosted websites. Deterministic evaluators check the agent's answer and captured network traces.
Muse Spark 1.1 69% - MobileWorld In use Agents complete 201 tasks across 20 mobile apps, including tasks that need user clarification or MCP tools. Backend checks verify success. Kimi K3 74.4%